• 환경위생공학
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• 제17권3호
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• pp.115-120
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• 2002

This study was performed on a questionnaire survey of 500 people about their awareness for indoor air pollution, and measured efficiency of air cleaner which can remove the CO and air-borne particulate of ETS(Environmental Tobacco Smoke) in air clean chamber. The room-size cleaner for measuring indoor air contaminants has been applied to evaluation of two different air cleaner such as the mechanic air cleaner with hepafilter(HPA) and the electrostatic air cleaner with metal plate. The measuring experiment was carried out in a chamber by sampling the air. The results obtained were as follows; As respondents are having their 90% of daytime indoors a day, and 38% of them can feel indoor air pollutions degrees directly by their sense of smell, For the installation of indoor pollution control equipment, 34% of all respondents installed air cleaner because of the problem of economical charge and almost respondents was not satisfied the trust of ability purified indoor air pollutants. In the experimental results, it was found that more than 95% of CD and air-borne particulate of ETS were removed within 20 minutes. The reaction kinetics of removal pollutants was verified as the pseudo-first order, Finally, it appeared that the room-sire air cleaner can be applied to new technology for removing indoor air contaminants.

• International Journal of Precision Engineering and Manufacturing
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• 제7권4호
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• pp.40-46
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• 2006

The market of programmable implantable pumps has bound to a monopolistic situation, inducing high device costs, thus making them inaccessible to most patients. Micro-mechanical and medical innovations allow improved performances by reducing the dimensions. This affects the consumption and weight, and, by reducing the number of parts, the cost is also affected. This paper presents the procedure followed to design an innovative implantable drug delivery system. This drug delivery system consists of a low flow pump which shall be implanted in the human body to relieve pain. In comparison to classical known solutions, this pump presents many advantages of high interest in both medical and mechanical terms. The first section of the article describes the specifications which would characterize a perfect delivery system from every points of view. This concerns shape, medication, flow, autonomy, biocompatibility, security and sterilization ability. Afterwards, an overview of existing systems is proposed in a decisional tree. Positive displacement motorized pumps are classified into three main groups: the continuous movement group, the fractioned translation group and the alternative movement group. These systems are described and the different problems which are specific to these mechanisms are presented. Since none of them fully satisfy the specifications, an innovation is justified.. The decisional tree is therefore extended by adding new principles: fractioned refilling and fractioned injection within the fractioned translation movement group, spider guiding system within the alternative translation movement group, rotational bearing guided device and notch hinge guided device in the alternative rotation movement group.

• Journal of Biosystems Engineering
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• 제37권2호
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• pp.90-99
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• 2012

Purpose: This study was conducted to investigate the optimal sorting factors in establishing an efficient sorting technology for brown rice. Methods: The brown rice varieties used in this study were Il Pum, Chu Cheong, Dong Jin, Un Gwang, Nam Pyeong, and Dae An. These were classified into whole grain, unriped grain, and green dead rice. The shape factors were analyzed based on length, width and thickness of the grains. Results: The results revealed that the maximum length among whole grain, unriped grain, and green dead rice was observed in Dae An variety while Chu Cheong variety showed the minimum. Further more, Il Pum brown rice showed the maximum width while Dong Jin variety showed the minimum. In the case of thickness, the maximum was observed in Un Gwang variety and that of the minimum among Nam Pyeong variety for both whole grain and unriped grain. Conclusions: The length and width can be used as determinants in sorting factors of whole grain and green dead rice, and the thickness can be considered as optimum sorting factor of whole grain and unriped grain.

• 한국의류학회지
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• 제32권5호
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• pp.681-691
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• 2008

Taking into consideration both the inconveniences reported with current working uniform for the aircraft mechanics and the subjects' requirements mentioned in preceded survey, the researchers designed an ergonomic sample garments with improved motional flexibility and comfort. To improve motional flexibility, extra folds were added to the back of the garments to allow for ease of motion of limbs, so that the material would not be drawn up by the motion of the arms. Darts were added to the elbow, hip, the knee. Furthermore, by increasing the length of the waist centerline, the hip region would not be drawn up. For improved comfort, $CoolMax^{(R)}$ was used as lining material for the armpit and back region to discharge swear promptly. Subjects and panels were asked to evaluate the sample garment that followed an ergonomic design and pattern. According to the results, the sample garment was evaluated more highly than the existing working uniform in appearance and motional flexibility. The field tests by three aircraft mechanics working in the Office of Forestry were also demonstrated that the sample garment was advanced in terms of motional flexibility and comfort.

• 센서학회지
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• 제4권1호
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• pp.29-34
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• 1995

SDB웨이퍼를 이용하여 절대압을 감지할 수 있는 압저항형 실리콘 다이아프램 압력센서를 제조하였다. 제조된 센서는 브릿지 형태로 연결된 4개의 압저항과 인가되는 압력에 대한 기계적인 증폭기 역할을 할 수 있는 다이아프램으로 구성되어 있다. 다이아프램 공극(cavity)을 낮은 진공상태로 만들기 위해 실리콘 다이아프램과 Pyrex 7740유리를 0.02mmHg, $400^{\circ}C$에서 정전 접합하였다. 제조된 센서의 감도와 오프셋 전압은 각각 $30.4{\mu}V/VmmHg$, 30.6mV였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.251-257
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• 1998

Spherical space frame structure with triangular network pattern, which has the various characteristics for the mechanic property, a funtional property, an aesthetic property and so on, has often been used as one of the most efficient space structures. It is expected that this type will be used widely in large-span structural roofs. But because this structure is made of network by combination of line elements there me many nodes therefore, the structure behavior is very complicated and there can be an overall collapse of structure by buckling phenomenon if the external force reaches a limitation. This kind of buckling is due to geometric shape, network pattern, the number of layer and so on, of structure. Therefore spherical space frame with triangle network pattern have attracted many designers and researchers attention all over the world. The number of layer of space frame is divided in to the simgle, double, multi layer. That is important element which is considered deeply in the beginning of structural design. The buckling characteristics of single-layer model and double-layer model for the spherical space frame structure with triangular network pattern are evaluated and the buckling loads of these types are compared with investigation their structural efficiency in this study.

• 한국생활과학회지
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• 제8권3호
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• pp.525-534
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• 1999

The purpose of this study is to analize in the focus on junk art the relation between hairstyle and dress, and fine art which is one of the driving force of fashion change. The method of this study is to take into theoretically consideration junk art in the trend of art and to take into documental concideration the trend of junk art reflected on hairsyyle and dress. The results are as following. First, there's a trait of poverty. This means using something deserted in our life and expands a new expression world which introduces a new, poor beauty, refusing a existent, rich and arranged one. Second, there's a trait of machinery. In Junk Art, according to the appearance of the beauty of machines, it creates and introduces a mechanic aesthetics as a new- formative art by using industrial by-product. Third, there's a trait of nature. By Junk Art, there appears a trial to restore nature which has been neglected under the name of developing science technology. This expresses natural junk factor by emphasizing the nature itself using natural by-products. The Junk Art has influence on hairstyle and clothing and expands the expression world by some new ways and recognition about the benefaction and the damage of modern civilization.

• 대한치과기공학회지
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• 제18권1호
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• pp.39-65
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• 1996

The purpose of this to inquire of the people who run a dental mechanical laboratory having troubles to manage and to find out the reform measures on the point at issue. With having done random sampling for the chiefs of dental mechanical labs across the nation, and then marking the analysis of the data for the survey, I came to a conclusion to be as follow. 1. The operating problems in dental mechanical laboratory in Korea is that it is too near at hand that the requested days for the manufacture of dental prosthesis appliances form dental clinics(45%)(P<0.01) 2. The problem of dental mechanic manpower was due to a small salary and inferior working environment(35% each)(P<0.01) 3. Some of them discount dental mechanical charges in manufacturing dental prosthesis appliances(36.7%)(P<0.01) 4. Many of them employed unlicensed dental technicians(61.7%)(P<0.01) As a counterplan for the aforementioned, I think that the whole dental mechanics should cooperate in breaking off the customary custom to allow a discount on the dental mechanical charges and readjust the dental mechanical charge to a realistic level so as to contribute to the development of the dental mechanical community and the vetterment of the public oral hygience.

• 복식문화연구
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• 제10권6호
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• pp.718-734
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• 2002

The purpose of this study is to provide basic data f3r improvement in Working Uniform in both scientific and efficient ways. The study were enforced by questionnaire and personal interview. The subject of the survey were the workers of 264 in mechanic industry in Seoul. The results obtained from the researches by methods above are as follows. 1. In general, Working Uniform could be classified types of two. One is loose-fitting one-piece garment covering the body and legs, the other is two-piece garment. The latter is a jacket with either sports collar or soutein collar, fastened with either buttons or a zipper and its sleeve is finished by cuffs and tapes. Regarding to color. inkblue, dark navy, khaky, dark beige are favourable ones. 2. In regard to the necessity of uniform that workers suppose, most of them were aware of it and agreed wearing uniform could play an important part. The reason why are on the basis of safety-first and work efficiency and also to protect a body from harmful or toxic dirt specially in machinery workplace. 3. The purpose of wearing an uniform according to statistics of population make some difference in age, gender. categories of industry, and the scale of factory. 4. In regard to care of uniform, front hem, edge of sleeve in a jacket, and knee, hip part in pants were most vulnerable spots for dirt. The parts damaged easily are edge of sleeve in a jacket and a zipper in pants. On the average, laundry have been done by water and was once a week frequency.

• Steel and Composite Structures
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• 제18권3호
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• pp.659-672
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• 2015

This research deals with the analytical solution of a curved beam with different shapes made of functionally graded materials (FGM's). It was assumed that modulus of elasticity is graded along the thickness direction of curved beam based on a power function. The beam was loaded under pure bending. Using the linear theory of elasticity, the general relation for radial distribution of radial and circumferential stresses of arbitrary cross section was derived. The effect of nonhomogeneity was considered on the radial distribution of circumferential stress. This behavior can be investigated for positive and negative values of nonhomogeneity index. The novelty of this study is application of the obtained results for different combination of material properties and cross sections. Achieved results indicate that employing different nonhomogeneity index and selection of various types of cross sections (rectangular, triangular or circular) can control the distribution of radial and circumferential stresses as designer want and propose new solutions by these options. Increasing the nonhomogeneity index for positive or negative values of nonhomogeneity index and for various cross sections presents different behaviors along the thickness direction. In order to validate the present research, the results of this research can be compared with previous result for reachable cross sections and non homogeneity index.